Adds action for tests

.github/workflows/tests.yml

@@ -0,0 +1,36 @@
+name: Tests
+
+on: ['push', 'pull_request']
+
+jobs:
+  ci:
+    runs-on: 'ubuntu-latest'
+    strategy:
+      fail-fast: true
+      matrix:
+        php: [8.1, 8.2, 8.3]
+        dependency-version: [prefer-lowest, prefer-stable]
+
+    name: Tests PHP ${{ matrix.php }} - ${{ matrix.dependency-version }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Cache dependencies
+        uses: actions/cache@v1
+        with:
+          path: ~/.composer/cache/files
+          key: php-dependencies-${{ matrix.php }}-composer-${{ hashFiles('composer.json') }}
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          coverage: none
+
+      - name: Install Composer dependencies
+        run: composer update --${{ matrix.dependency-version }} --no-interaction --prefer-dist
+
+      - name: Run Tests
+        run: composer test